1. Field of the Invention
The present invention relates to a control guide member for controlling the oil flow through the windings of transformers, reactors and similar oil-cooled apparatus.
2. The Prior Art
In transformers the windings are as a rule surrounded by vertical insulating cylinders so that the windings are located in annular axial channels. In these the oil flows upwards past the windings and cools them. If no special measures are taken, the cooling will be very uneven since the outermost turns in a winding disc in the case of disc winding or in a winding layer in the case of layer winding will be much better cooled than the inner layers which are located exactly between the axial cooling channels between the winding and the insulating cylinders.
In order to force the upward oil flow to move also in radial direction through the radial channels between disc and layers, it has been proposed to insert at certain intervals radially directed guide members which extend from the insulating cylinders into the radial channels. The guide members then extend alternately from one and from the other insulating cylinder. By such an arrangement of guide members there is obtained a zig-zag-formed oil flow through the winding from one axial side to the other. To attain a uniform cooling of all discs and layers, however, one guide member for each disc and layer is required. This involves a very long flow path and a high flow resistance, and also leads to too great a difference in the temperature of the oil between the ends of the winding. Therefore the guide members are placed at considerably greater distances from each other in the axial direction, but this in turn leads to an uneven cooling of the discs and the layer between two guide members, since the radial channel, lying on top of a disc having a control guide member under it, has a very small radial flow of oil and is therefore badly cooled.